1. Field of the Invention
The present invention relates to a passenger seat for vehicles such as buses, railway cars, ships and airplanes.
2. Description of the Prior Art
Two types of passenger seats are generally employed for passenger vehicles, economy and luxury seats. The economy seats which are usually installed in vehicles which are used by passengers only for relatively short rides, are, in accordance with their intended use, of relatively simple construction and have little but extremely well-wearing upholstery, generally with plastic cover materials. Particularly, neither the seating portion nor the backrest are tiltable but both are firmly mounted on a seat base. In contrast, luxury seats have relatively thick upholstery, have a substantially more sensitive woven, plush cover material such as velour, and they are usually adjustable for various seating positions as desired. Adjustment may be possible with regard to the angle between the seating portion and backrest as well as between the seating portion and the floor of the vehicle.
All passenger seats however have to be capable of carrying not only the passenger load but also of withstanding the acceleration and deceleration forces including those induced by the passenger load. The passenger seats have to be strong enough to firmly support or retain the passenger, for example during an accident, but they also have to be rigid enough that unused seats do not rattle, that is, all connections as well as all joints have to be fully rattle-free.
In order to meet all these requirements, vehicle passenger seats have, so far, included tubular support structures of great rigidity. They have generally included a base constructed of round or even rectangular tubes supporting a seating frame to which a support structure for the backrest was mounted which, too, included a tubular support frame. For the mounting of the upholstery, a plate-type carrier usually consisting of plywood was mounted into each the seating and the backrest frame.
Vehicle seats of such a design usually meet all the requirements listed as they can be made in this manner to be very sturdy and they do not pose any design problems. Their disadvantage is, however, that they are relatively heavy so that a vehicle provided with such seats always has to carry a substantial dead weight. In addition, of course, seats of the type described are expensive to manufacture because the tubular frames have to be bent and interconnected by special connecting elements.
It is accordingly desirable to provide a seat which is simple and relatively inexpensive to manufacture and which meets all requirements with respect to rigidity but, nevertheless, is relatively light.